This invention relates to an apparatus for cutting a sheet material such as a fabric in the form of a laminate consisting of a number of sheets.
An example of a conventional cutting apparatus of this type has been proposed by the inventor in Japanese Patent Application Laid Open (KOKAI) No. 63-267190. This conventional apparatus includes a pedestal having a supporting surface provided with a transversely extending guide groove, a cutting receiving plate having a cutting receiving sleeve, and closure plates connected to both ends of the receiving plate, with the cutter receiving plate and closure plates being fitted into the guide groove. The upper surfaces of the cutter receiving plate, closure plates and supporting surface are disposed so as to be flush or substantially flush. Suction pipes for withdrawing air from both side surfaces of the laminate supported on the supporting surface are disposed on the supporting surface, a cutter head is supported above the cutter receiving plate so as to oppose the same, and a cutter inserted into the cutter receiving sleeve is mounted on the cutter head so as to be capable of moving up and down.
With this cutting apparatus, the laminate is supported on the supporting surface. The laminate consists of multiple plies of a sheet material such as fabric, and the major portion of the outer peripheral surface, inclusive of the top and bottom sides of the laminate, is covered with an air-impermeable sheet. Owing to the sucking action from the suction pipes, both side faces of the laminate are fixedly attracted to the suction pipes, in which state the laminate is supported on the supporting surface. The cutter is lowered so that its lower end is fitted into the cutter receiving sleeve, the suction pipes are reciprocated in the longitudinal (X) direction along with the laminate by a longitudinal drive mechanism, the cutter head and the cutter receiving plate are reciprocated synchronously in the transverse (Y) direction by a transverse driving mechanism, and the cutter head and cutter receiving sleeve are turned synchronously about their axes, whereby the laminate is cut into a desired shape.
A problem encountered in the conventional cutting apparatus described above is that as cutting proceeds, the fixed relationship among the stacked sheets diminishes at portions where cutting has ended, and therefore the sheets become positionally displaced relative to one another owing to friction at the immobile supporting surface. The result is that cutting cannot be performed accurately.